The progress of a normal maternal delivery is generally driven by two types of labor forces: a primary force produced by the involuntary contractions of the uterine muscles, and a secondary force produced by the increase of intra-abdominal pressure through voluntary contractions of the abdominal muscles and diaphragm. During the labor process, these two forces are designed to work concurrently to provide an increase in intrauterine pressure that supplies the critical expulsion force on the fetus. Ideally, the maternal patient will attempt to voluntarily contract her abdominal muscles to directly coincide with the forces of the involuntary uterine contractions or the instructions provided by a healthcare provider.
However, through the implementation of the commonly-employed epidural anesthesia, the overall ability of the maternal patient to manage and direct the secondary force can be reduced significantly. By blocking the transmission of signals through nerves in the spinal cord, the epidural not only causes a loss of pain for the maternal patient, but also results in the overall loss of muscular sensation, especially sensation to the abdominal muscles used in the birthing process. Thus, following an epidural, the maternal patient often cannot tell how much force is being exerted through the abdominal muscles when “pushing,” or whether she is actually pushing at all. Indeed, in some cases, the maternal patient can have difficulty isolating and pushing with the correct muscles. In the worst case, the patient voluntary pushing may be completely out of phase from the uterine contraction, thus counteracting the desired progression of labor.
What is needed, therefore, is a system and method that indicates when a maternal patient should push and reports to the attending physician and patient whether the push was an “effective push,” or a push that verifiably progressed the labor toward delivery.